Yes, you can do that, but you're thinking about it wrong. What you want to do is output to the surface transparency the value held in an images Alpha channel.
In your Surface Properties shader add a Texture object. Load your texture with Alpha channel. Set the output of the texture object (In/Out tab) to Surface:Transparency In the Bindings tab, click the Edit checkbox and set the bindings so the Transparency's RG and B channels (destination) are set from the source image's A channel At this point I'll mention I can't actually do this because RS's window is busted and has been as long as I've known the software. When I click Edit Binding the Source panel extends to below the bottom of the window and I see no destination panel. No amount of opening and closing windows and panels and Ctrl left right shift click and dragging will expose the rest of the interface for me. The way panels auto scale and such I've always found awkward as they invariably produce a window far longer than my 768 pixel height display, and often don't terminate at the bottom of the window anyway. Anyway, what you are doing is selecting a picture that has Red, Green, Blue and Alpha components, and saying 'For each pixel, take the images Alpha value and set that as the transparency value of the Red, Green and Blue colour components of the surface.' You can just as easily create a black and white image and set the value of surface transparency to the red component of the image, using it as a mask. David Coombes [EMAIL PROTECTED] ... ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, April 29, 2006 11:56 AM Subject: VSL: Testing an image for an alpha channel > Hi, is it possible to test for the prescence of an alpha channel in a > given image map inside a VSL material? > > Something like: > > Surface properties > { > do stuff > > if (image has alpha) > { > Apply alpha channel of image to surface transparency > } > } > > I want to use the same structure of the VSL material for all my > objects to let users simply change the possible parameters that match > the in-game material properties without having to modify the actual > VSL code. > > Regards, > Fredrik Bergholtz >
